Rdio discussion board post pretty much goes like this.
Guy 1: Uhh – Rdio streaming is horrible!! Not as good as spotify by far.
Guy 2: No way. I have a Soundblaster XTIWTFBBQ and Rdio sounds as good as my 320kbps MP3s.
Rdio: We limit the bitrate on 3G streaming so your cell phone company doesn’t screw you over. We stream CD quality everywhere else.
Guy 3: CD Quality? P’shaw! What do you think that means?
Guy 4: Rhapsody sounds the best!
Guy 1: There’s no mids in the Rdio streams!